Buggy code:
public class MapgenEntry implements Jsonable { private static final char [ ] SYMBOLS = new char [ ] { 'a' , 'b' , 'c' , 'd' , 'e' , 'f' , 'g' , 'h' , 'i' , 'j' , 'k' , 'l' , 'm' , 'n' , 'o' , 'p' , 'q' , 'r' , 's' , 't' , 'u' , 'v' , 'w' , 'x' , 'y' , 'z' , 'A' , 'B' , 'C' , 'D' , 'E' , 'F' , 'G' , 'H' , 'I' , 'J' , 'K' , 'L' , 'M' , 'N' , 'O' , 'P' , 'Q' , 'R' , 'S' , 'T' , 'U' , 'V' , 'W' , 'X' , 'Y' , 'Z' , '1' , '2' , '3' , '4' , '5' , '6' , '7' , '8' , '9' , '0' , '!' , '@' , '#' , '$' , '%' , '^' , '&' , '*' , '(' , ')' , '-' , '_' , '=' , '+' , '[' , '{' , ']' , '}' , ':' , ';' , '"' , '\'' , '<' , ',' , '>' , '.' , '?' , '//' , '`' , '~' , '\\' , '|' , '<seq2seq4repair_space>' } ; private static Logger log = LogManager . getLogger ( MapgenEntry . class ) ; protected String [ ] [ ] terrain = new String [ MapEditor . SIZE ] [ MapEditor . SIZE ] ; protected String [ ] [ ] furniture = new String [ MapEditor . SIZE ] [ MapEditor . SIZE ] ; protected List < PlaceGroupZone > placeGroupZones = new ArrayList < > ( ) ; protected MapSettings settings = new MapSettings ( ) ; protected MapgenEntry ( ) { } public MapgenEntry ( final MapgenEntry mapgenEntry ) { } @ Override public boolean equals ( Object o ) { } @ Override public int hashCode ( ) { } private List < String > createRandomGrass ( ) { boolean [ ] [ ] grassArray = new boolean [ MapEditor . SIZE ] [ MapEditor . SIZE ] ; for ( int x = 0 ; x < ( MapEditor . SIZE ) ; x ++ ) { for ( int y = 0 ; y < ( MapEditor . SIZE ) ; y ++ ) { <START_BUG> grassArray [ x ] [ y ] = terrain [ x ] [ y ] . equals ( "t_grass" ) ; <END_BUG> } } List < MapgenEntry . Rectangle > grassRectangles = new ArrayList < > ( ) ; for ( int x = 0 ; x < ( MapEditor . SIZE ) ; x ++ ) { for ( int y = 0 ; y < ( MapEditor . SIZE ) ; y ++ ) { if ( ! ( grassArray [ x ] [ y ] ) ) { continue ; } int y2 = getGrassY2 ( x , y , grassArray ) ; int x2 = getGrassX2 ( x , y , y2 , grassArray ) ; MapgenEntry . Rectangle r = new MapgenEntry . Rectangle ( ) ; r . x1 = x ; r . y1 = y ; r . x2 = x2 ; r . y2 = y2 ; for ( int ix = r . x1 ; ix <= ( r . x2 ) ; ix ++ ) { for ( int iy = r . y1 ; iy <= ( r . y2 ) ; iy ++ ) { grassArray [ ix ] [ iy ] = false ; } } grassRectangles . add ( r ) ; } } List < String > grassEntries = new ArrayList < > ( ) ; for ( MapgenEntry . Rectangle r : grassRectangles ) { String grassEntry = "{<seq2seq4repair_space>\"point\":<seq2seq4repair_space>\"terrain\",<seq2seq4repair_space>\"id\":<seq2seq4repair_space>\"t_dirt\",<seq2seq4repair_space>" ; if ( ( r . x1 ) == ( r . x2 ) ) { grassEntry += ( "\"x\":<seq2seq4repair_space>" + ( r . x1 ) ) + ",<seq2seq4repair_space>" ; } else { grassEntry += ( ( ( "\"x\":<seq2seq4repair_space>[<seq2seq4repair_space>" + ( r . x1 ) ) + ",<seq2seq4repair_space>" ) + ( r . x2 ) ) + "<seq2seq4repair_space>],<seq2seq4repair_space>" ; } if ( ( r . y1 ) == ( r . y2 ) ) { grassEntry += ( "\"y\":<seq2seq4repair_space>" + ( r . y1 ) ) + ",<seq2seq4repair_space>" ; } else { grassEntry += ( ( ( "\"y\":<seq2seq4repair_space>[<seq2seq4repair_space>" + ( r . y1 ) ) + ",<seq2seq4repair_space>" ) + ( r . y2 ) ) + "<seq2seq4repair_space>],<seq2seq4repair_space>" ; } int area = ( ( ( r . x2 ) - ( r . x1 ) ) + 1 ) * ( ( ( r . y2 ) - ( r . y1 ) ) + 1 ) ; int repeatMin = Math . max ( Math . min ( ( ( ( int ) ( area // 3.5 ) ) - 1 ) , 8 ) , 0 ) ; int repeatMax = Math . min ( Math . max ( ( ( ( int ) ( area // 2.5 ) ) - 1 ) , 1 ) , 14 ) ; grassEntry += ( ( ( "\"repeat\":<seq2seq4repair_space>[<seq2seq4repair_space>" + repeatMin ) + ",<seq2seq4repair_space>" ) + repeatMax ) + "<seq2seq4repair_space>]<seq2seq4repair_space>}," ; grassEntries . add ( grassEntry ) ; } return grassEntries ; } private int getGrassY2 ( final int x , final int y , final boolean [ ] [ ] grassArray ) { } private int getGrassX2 ( final int x , final int y , final int y2 , final boolean [ ] [ ] grassArray ) { } private static class Rectangle { private int x1 ; private int y1 ; private int x2 ; private int y2 ; @ Override public String toString ( ) { } } @ Override public List < String > getJsonLines ( ) { } private Map < MapTile , Character > mapSymbols ( ) { } }

Fix:
grassArray [ x ] [ y ] = ( terrain [ x ] [ y ] . equals ( "t_grass" ) ) && ( furniture [ x ] [ y ] . equals ( "f_null" ) ) ;